RSV Vaccine

Learn about the options available to help protect your baby against Respiratory Syncytial Virus (RSV) during their first months of life.

Quick Facts

  • RSV is a common virus that spreads easily.

    Respiratory syncytial virus (RSV) is a virus that infects the nose, throat, and lungs. It is most common in the fall and winter months and spreads easily through coughs, sneezes, or contact with contaminated surfaces.

  • Newborn babies are most at risk of severe RSV.

    Babies under 6 months are more likely to get very sick from RSV. It can cause serious breathing problems and lung infections and is a leading cause of hospitalization in babies under 1 year old.

  • There are new options available to protect babies from RSV.

    Pregnant people can get the RSV vaccine (RSVpreF) during pregnancy, or babies can get an RSV antibody (Nirsevimab) shortly after birth. The best option depends on availability, cost, and personal preference.

  • The maternal RSV vaccine is given in the third trimester of pregnancy.

    The RSVpreF vaccine is recommended between 32 and 36 weeks of pregnancy. After vaccination, your body makes protective antibodies that are passed to your baby through the placenta, helping protect them from RSV after birth.

  • The maternal RSV vaccine helps protect babies from severe illness.

    Babies whose parent got the RSV vaccine during pregnancy are much less likely to get seriously ill or need hospital care. Protection lasts up to 6 months after birth, when babies are most vulnerable.

  • The maternal RSV vaccine is safe in pregnancy.

    The RSVpreF vaccine was specially designed and tested for use during pregnancy. Studies confirm it is safe for both pregnant individuals and their babies and does not increase the risk of complications.

Protecting Against RSV

Respiratory Syncytial Virus or ‘RSV’ is a highly contagious virus that can cause serious illness in young babies. Around 20 to 30% of babies who get RSV develop serious infections like bronchiolitis (inflammation of the small airways) or pneumonia (lung infection).¹⁻³ 

Babies are most vulnerable to severe RSV infections in the first few months after they are born. Fortunately, there are new options available to help protect babies from severe RSV illness.

  • Graphic of a pregnant woman holding belly

    Maternal RSVpreF Vaccine (Abrysvo)

    Pregnant people can get this vaccine between 32 and 36 weeks of pregnancy. It helps the body make protective antibodies, which are passed to the baby through the placenta before birth. These antibodies help protect the baby from RSV in the first months of life. The vaccine was specially designed and tested for use during pregnancy.⁴

  • Graphic of a newborn baby

    Infant RSV Antibody (Nirsevimab)

    Babies can get this one-time injection soon after birth (if they are born during RSV season) or just before or at the start of the season. Instead of teaching the body to make its own antibodies, this shot gives babies ready-made antibodies that begin working right away and help protect them during the first few months of life, when the risk of serious RSV illness is highest.⁴

About RSV

Respiratory syncytial virus (RSV) is a common seasonal virus that spreads easily from person to person. Each year, RSV causes millions of hospitalizations and around 120,000 deaths worldwide in children under the age of five.⁵

RSV is especially dangerous for babies in their first 6 months of life.²˒⁶ A study of children’s hospitals across Canada found:

  • Half of all RSV hospitalizations were in babies under 6 months old.²

  • Nearly 40% were in babies between 0 and 2 months old.²

  • About 60% of babies who needed intensive care were between 0 and 5 months old.²

RSV infections usually start with symptoms like a runny nose, dry cough, low-grade fever, sore throat, and sneezing. But in young babies, it can become more serious and lead to bronchiolitis (inflammation of the small airways in the lungs) or pneumonia, which can cause severe cough, wheezing, and difficulty breathing.

RSV is most dangerous for babies during their first six months of life.

Maternal RSVpreF Vaccine (Abrysvo)

The maternal RSVpreF vaccine (Abrysvo™) was approved by Health Canada in 2023 to help protect newborns from serious illness caused by RSV.⁴ This vaccine was specially designed for use during pregnancy and has been tested in pregnant individuals around the world. It is given between 32 and 36 weeks of pregnancy. RSVpreF (brand name – Abrysvo) is the only RSV vaccine currently recommended for use during pregnancy in Canada.

After vaccination, your body makes infection-fighting antibodies that pass through the placenta to your baby. These antibodies help protect your baby during the first few months of life, when they are most at risk of becoming seriously ill from RSV. The vaccine targets the two most common types of RSV in Canada and helps protect your baby for up to 6 months after birth.⁴

When you get the RSV vaccine in pregnancy, you pass protective antibodies to your baby that help protect them from RSV after they are born.

Infant RSV Antibody (Nirsevimab)

The RSV infant antibody (Nirsevimab) is a type of RSV protection given to babies as a single shot shortly after birth. It contains ready-made antibodies that help protect your baby right away. This is called passive immunization—instead of your baby’s body making its own antibodies, they’re given directly through the shot. These antibodies work by blocking the RSV virus from entering your baby’s cells. That helps stop the virus from spreading and causing serious illness.13

Research shows that Nirsevimab protects babies from severe RSV illness and hospitalization for at least 5 months after they are born, which covers a typical RSV season.13 This early protection matters because babies are most at risk of getting very sick from RSV in their first few months of life. As of 2025, Nirsevimab is available in some provinces and territories in Canada, but not all. Talk to your healthcare provider to find out what’s available in your area.

Which Option is Best for Me and My Baby?

As of 2025, only one RSV protection option is recommended for each baby—either the maternal RSV vaccine during pregnancy or the infant RSV antibody given after birth. Each option provides strong protection on its own, and using both hasn’t been shown to offer any extra benefit for most babies. This recommendation could change in the future as more research becomes available. While both options are safe and effective, the best choice for you may depend on things like what’s available in your province or territory, your personal preferences, and whether the cost is covered by your province or territory.

As of Fall 2025:

  • The RSV antibody (Nirsevimab) is available in some provinces and territories across Canada, but not all. In some areas, Nirsevimab is only available for babies at higher risk of severe RSV illness, such as those born prematurely (before 37 weeks), those with certain lung or heart conditions, or babies living in very remote communities. 

  • The maternal RSVpreF vaccine (Abrysvo) is currently only publicly funded in Ontario, where eligible pregnant individuals can get it for free. In all other provinces and territories, the maternal RSVpreF vaccine can be purchased at select pharmacies with a prescription from a healthcare provider. Some private insurance plans may help cover the cost. 

Scroll through the boxes below to see what’s currently available in each province and territory. Programs and coverage may change, so it’s a good idea to talk with your healthcare provider about the best option for you and your baby.

RSV Vaccine Safety

RSV Vaccine Timing

Additional Information

Both the maternal RSVpreF vaccine and the infant antibody help protect young babies from severe illness and hospitalization.

Key Facts